It has been possible to run Hadoop on EC2 for a while. Today Amazon simplified the process by announcing Amazon Elastic MapReduce which automatically deploys EC2 instances for computational use and includes a API for interacting with them.
Cascading is a new processing API for data processing on Hadoop clusters, and supports building complex processing workflows using an expressive, declarative API.
Aster Data Systems has announced an in-database MapReduce implementation for their nCluster database platform.
The MapReduce design pattern to distribute data processing was introduced by Google in 2004, and came first with a C++ implementation. A new Ruby implementation is now available under the name of Skynet released by Adam Pisoni. InfoQ had the chance to catch up with Adam about its features and how it compares to an existing Ruby implementation called Starfish.
A recent article on the Database Column by David J. DeWitt and Michael Stonebraker attempts to compare the increasingly popular MapReduce programming paradigm to a relational database. The blogsphere has quickly called foul on the comparison and its reasoning.
Amazon's EC2 Elastic Computing cloud allows developers to acquisition computing power a the rate of $0.10 per hour consumed. Work as been done to allow Hadoop an open source MapReduce implementation written in Java to run on EC2. This combination will allow developers to write scalable algorithms and then bring up large numbers of servers to use as computing power for them as needed.